Enzymes

Question 1

Explain the mechanism by which the extract from the kidney bean inhibited the amylase.

Answer 1

.competes with substrate
.blocks active site
.prevents substrate from entering active site

Question 2

Explain why there is a difference in the shapes of the curves at 37 °C and 60 °C.

Answer 2

.60°C more kinetic energy therefore more, successful collisions
.initial rate (of reaction) faster ✓

Question 3

Explain why there is a difference in the shapes of the curves at 25 °C and 37 °C.

Answer 3

.At lower temperature / 25°C
less kinetic energy therefore less, successful collisions
.rate (of reaction) slower / taking
more time for product to be formed

Question 4

There are two models for the mechanism of enzyme action. Outline how changes in
temperature can affect these mechanisms of lipase action.

Answer 4

.enzyme‐substrate complex formed
.enzyme‐product complex formed
.product(s) leave the active site
.lock and key = shape of substrate and enzyme’s active site are complementary and so enzyme is specific
.induced fit = enzyme active site changes shape to accommodate substrate once substrate binds
.increase in temperature increases kinetic
energy of molecules
.results in more successful collisions
.more enzyme‐substrate complexes form